A dip in your solar panel system’s performance could mean that pollen, dust and dirt are preventing the sun from reaching the solar cells and keeping your energy bills low.
Discover if, when and how solar panels should be cleaned to boost their efficiency without risking damage. It’s best to get a professional in to clean them, to avoid the risks of invalidating your insurance, product warranty or injuring yourself.
EASY AS HACK
Using a specialist cleaning service will reduce the risk of damaging the panels, which could invalidate the warranty, and the chance of injuring yourself. However, if you do decide to clean your solar panels, keep it simple and use a light water-spray with a hose, keeping your feet on the ground, without a ladder.
At a glance
- Call in the experts if your solar panels are above the first floor
- Read your maintenance manual and warranty before you start solar panel cleaning
- Turn off your solar panel system
- Use a soft brush, sponge and water – avoid using soap
why should you clean your solar panels?
You should clean your solar panels because debris like twigs and leaves, bird droppings, dust, and lichen growth can affect their efficiency and power generation. Cleaning can also prolong the life of components in domestic and commercial rooftop systems.[1]
how to clean your solar panels
Knowing how to clean your solar panels is essential as it can be done in various ways, from a gentle hose-down with water to professional cleaning by a company.
The level of solar panel cleaning will depend on the type of debris but remember that solar panels are delicate. You must call in an expert trained in working with hazardous substances if chemicals are required (for example, to remove lichen).[1] Check your maintenance manual first, before cleaning or working on a solar system and turn off the power before cleaning it.[1]
method 1: soap-less brushes and sponges
Health and safety is essential, especially at heights, which is why we recommend hiring a professional for cleaning and maintenance. It’s dangerous to clean solar panels from a ladder without health and safety training.
Using chemicals like detergent can also invalidate your warranty. Always consult the manual before undertaking any cleaning. However, once you have turned off the system, you can use a soft brush, water and a sponge to remove dust, pollen and other dirt from solar panels if you can reach them from the ground.[2]
If your solar panels are not easy to reach, clean the panels on the roof from the ground using a hose and water.[3]
method 2: manual cleaning
An effective way to clean your solar panels manually is to stand at ground level and use a hose.[2] You can also use equipment designed specifically for solar panels, so you don’t damage them.[1]
Some soaps leave a residue, so either use mild, soapy water[5] or an approved solar panel cleaning solution. However, water is the safest.[4] Again, check your manual and warranty first.
method 3: low-pressure power sprayer
Avoid high-power water jets that can scratch the surface of your panels. You could use a low-pressure power wash if the solar panel manufacturer approves it, but a standard hose will work without the risk of damaging your panels[5]
method 4: nanoparticle coatings
Some solar panels have a coating of nanoparticles that is said to be self-cleaning, reducing the amount of dirt built on the surface and maximising performance.[6] Despite this, if you live somewhere sandy or dusty, you may still need to clean them occasionally.[7]
tips for cleaning solar panels
- Check that your sponge is not abrasive, or you could scratch the panels[3]
- Avoid using soap and harsh chemicals for solar panel cleaning as they may leave a film[5] and damage equipment [1]
- Have the correct equipment at hand for safe use on solar panels[5]
- Don’t attempt cleaning solar panels if they are above ground level or it would invalidate your warranty
does cleaning your solar panels improve efficiency?
Solar panel cleaning is essential if you want to restore performance by removing dirt and extending your panels’ life [5]
Dust and debris like bird droppings on your solar panels’ surface can prevent light from reaching the cells, reducing efficiency.[5]
Regular inspections will help you to identify such issues.[7]
how often should solar panels be cleaned?
Some experts recommend cleaning your solar panels every six months [9]. But you may benefit from cleaning them more often depending on your home’s location:
- Polluted areas: Studies have found that pollutants can adversely affect solar panels’ function [10]
- Farmland: When farmers are spreading lime, the dust can land on nearby roofs and solar panels, damaging the frames.[1]
- Wooded areas: If you live close to trees, the leaves, branches and pollen can land on your solar panels, preventing the sun from reaching them.[4]
- Beaches: If you’re close to a beach or sandy area, sand on your panels can block the light or scratch the surface.[7]
how to check when your solar panels need cleaning
The installation, including the panels’ angle and roof access, will determine how often your solar panels need cleaning.[1] Inspect the panels at regular intervals or if you notice that they are less efficient.[4]
Also, check them when a specific event occurs, like large numbers of migrating birds leaving droppings on the roof or harvest time if you live near a farm.[1]
A monitoring system installed during the installation or retrofitted can build a performance history that includes underperformance due to excess dirt and lichen growth. The system can also show that you maintained your solar panels and the system in case of an insurance claim.[1]
Some insurers, including Ageas, cover solar panels under buildings insurance, but there may be exclusions for damage caused by cleaning, so make sure you check your policy wording.
Learn more about Ageas buildings insurance.
how much does solar panel cleaning cost
How much solar panel cleaning costs will depend on several factors:
- Cleaning them yourself is undoubtedly the cheapest option (unless you invalidate the warranty). However, if the solar panels are above ground level and you’re working at height it is safer to hire a professional.[1]
- How many panels you have will affect solar panel cleaning costs, as cleaning companies charge by the panel
- The solar panels’ location can impact costs. Solar panel cleaning costs an average of £15 per panel, with panels on the upper floors costing more than the ground floor.[9]
See more handy tips on protecting your home
Find out more about Ageas home insurance
FAQS
when is the best time of year to clean your solar panels?
Cooler seasons, like spring, are the best time of year to clean solar panels.[4] Clean them in the early morning or late afternoon with a water temperature specified by the manufacturer, as cold water sprayed on hot glass can cause thermal shock [1]
what cleaning equipment should i use?
When you’re cleaning your solar panels, use a soft brush and a squeegee with a plastic blade and non-abrasive sponge.
do you have to clean your solar panels?
You need to clean solar panels because dirt and debris build up and affect the amount of sunlight reaching the photovoltaic cells in them.
does rainwater clean your solar panels?
Most rainfall will remove dust and dirt if your panels are at the right angle, but even panels with self-cleaning coatings need intervention to remove stubborn grime or dirt.[5] It’s good practice to clean them regularly.[1]
do you have to turn off solar panels to clean?
Yes, you must shut down your solar panel system before cleaning it.
sources
[2] https://www.theecoexperts.co.uk/solar-panels/maintenance
[3] https://www.theecoexperts.co.uk/solar-panels/cleaning
[5] https://www.projectsolaruk.com/blog/how-to-clean-solar-panels-the-definitive-guide/
[6] Nanotechnology in Solar Cells: The Future of Solar Energy
[7] https://www.eonnext.com/solar-panels/solar-panels-guide/solar-panel-maintenance-and-cleaning
[9] https://www.checkatrade.com/blog/cost-guides/solar-panel-cleaning-cost/
